Income Taxes - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Unrecognized tax benefits			$ 27,314		$ 27,401
Unrecognized tax benefits that would impact effective tax rate	0		0		0
Estimated interest and penalties related to the underpayment of income taxes	16	179		160
Accrued interest and penalties related to the underpayment of income taxes	51		51		35
Liability for uncertain tax positions	$ 27,365		$ 27,365		$ 27,436